(1) Field of the Invention
This invention relates to a method of preventing defective germination or rosette formation of a plant seed, which tends to suffer from defective germination or rosette formation during growth thereof.
(2) Description of the Related Art
So far, a seed, which suffers from defective germination or rosette formation during growth thereof, has been subjected to health care of the seedling in a cell tray or a pot and kept at low temperature for a specific period of time, thereby the defective germination or rosette formation at high temperature is prevented from occurring.
When the seedling needs health care, since about thirty thousands seedlings per 10 ares of field are usually required, therefore it has been very difficult to carry out the health care of the seedling from the viewpoint of facilities or workability.
Therefore recently, a refrigerating treatment technique of seeds has attracted a considerable attention. However, in this technique sufficient amount of water has to be supplied to the seeds during the refrigerating treatment, therefore the seeds are immersed in water filled in a container, thereby the refrigerating treatment is carried out.
Among these seeds, which need the improvement in the defective germination or rosette formation at high temperature, there are ultra-micro seeds such as a seed of Eustoma russellianum, which are hard to sow even when they are in usual dried condition and all the more hard to sow when they are wet after the refrigerating treatment.
When the seeds are pelletized seeds, they are not suited to the preservation in cooling water, therefore the above refrigerating treatment technique is hard to utilize.
In this respect, a treatment has been proposed, in which the so-called “fluid gel” consisting of granular macromolecular water absorbing entity is employed and the seeds are uniformly dispersed in the fluid gel, then the seeds are sown with the fluid gel after the refrigerating treatment. However, when the seeds are dispersed in the fluid gel before the refrigerating treatment, the fluid gel takes off from the water, failing in holding the seeds.
When the seeds after the refrigerating treatment are dispersed in the fluid gel so as to sow, it is difficult to uniformly disperse the wet seeds after the refrigerating treatment in the fluid gel, therefore the accuracy of the sowing deteriorates bringing about a waste of seeds (that is, the thinning out being needed or positions at which the seeds are not sown being arisen).